As shown in Japanese Patent Application Laid-Open No. 2000-23313, a proposal has been made on a running gear for a hybrid vehicle in which: a first clutch is provided between a drive axle of an engine and a drive axle of a motor; and a second clutch is provided between a continuously variable transmission and driving wheels. This running gear for a hybrid vehicle disengages the first clutch during the deceleration of the vehicle. Thereby, the running gear is capable of causing the regenerative brake of the motor to work alone without allowing the engine brake to work on the driving wheels, and accordingly capable of efficiently collecting the energy produced by the brake regeneration due to the deceleration.
Nevertheless, the running gear for a hybrid vehicle as described in Japanese Patent Application Laid-Open No. 2000-23313 preferably keeps the first clutch engaged during the deceleration in some cases such as a case where no sooner is the first clutch released than the engine needs to be started. In such cases, the first clutch continues being engaged instead of being disengaged during the deceleration, and the motor and the engine are connected together via the first clutch. Accordingly, the regeneration efficiency decreases as a result of reduction in the regenerative energy due to lost torque of the engine.
An object of the present invention is to provide a shift controller and a shift controlling method which are capable of enhancing the regeneration efficiency.